Spray generator

ABSTRACT

A spray or mist generator produces a controllable moisture content stream of gas by combining a fluid distributing component with a gas moving component in a duct.

United States Patent 151 3,698,695 Andrews Oct. 17, 1972 SPRAY GENERATOR [56] References Cited [72] Inventor: John S. Andrews, Glamorganshire, UNITED STATES PATENTS Wales a 1,223,083 4/1917 L nn ....239/223 [731 Assgmi 1,289,779 12/l9l8 Hiaward .239/224 3,053,458 9/1962 Flury ..239/224 122 Filed: Dec.28, 1970 FOREIGN PATENTS OR APPLICATIONS 1211 Appl.No.: 101,857

1,170,236 11/1969 Great Britain ..26l/24 Foreign Application Priority Data April 25, 1970 Great Britain ..20,004/70 US. Cl. ..26l/24, 261/84, 239/224 Int. Cl. ..B0li 3/04 Field of Search .239/224, 223, 222.11; 261/118,

Primary Examiner-Tim R. Miles Attorney-Harry B. Keck and George E. Manias ABSTRACT A spray or mist generator produces a controllable moisture content stream of gas by combining a fluid distributing component with a gas moving component in a duct.

4 Claims, 3 Drawing Figures PATENTEDum 17 m2 SHEET 2 0F 3 SHEET 3 [IF 3 SPRAY GENERATOR BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to producing sprays or mists for use in suppressing dust in coal mines and for use in industrial ventilation systems where humidity control is desired.

2. Description of the Prior Art The present spray mist generator is an improvement over similar structure described in British Pat. No. 1,170,236 (J. S. Andrews, Nov. 12, 1969). The existing structure includes a motor driven fan and a hollow fairing carried by the shaft of and rotating at the same speed as the said fan. The fairing has a plurality of apertures adjacent to the periphery. An inlet tube delivers a liquid to the fairing through a central aperture in the fairing. The water forms a film and is discharged from the fairing in the form of a fine spray or mist through the peripheral apertures. The mist or spray is entrained by and combines with the airstream created by the fan. The humidity of the resulting airstream can be regulated by controlling the flow rate of liquid into the fairmg.

Centrifugal forces heretofore have been employed for generating atomized fluid particles, see U. S. Pat. No. 1,289,779 (W.'H. Howard,Dec. 3.1, 1918).

SUMMARY OF THE INVENTION The object of this invention is to provide an improvement or modification of the spray or mist generator which is described in British Pat. No. 1,170,236.

According to the present invention a motor driven shaft is mounted concentrically within a duct and carries a hollow coniform member and an annular fan. A liquid inlet tube enters the coniform member coaxially therewith. A dished fairing piece, fixedly carried by the inlet tube, is spaced-apart from the coniform member by an annular slit. The coniform member can also be described as a fluid distributing member having a central core portion, a rim, and therebetween, a rounded annular forwardly projecting surface. Adjustment means are provided for controlling the width of the annular slit whereby the size of the fluid droplets can be regulated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a broken longitudinal illustration partly in cross-section of a duct showing the present spray generator;

FIG. 2 is a longitudinal cross-sectional view illustrating an alternative embodiment; and

FIG. 3 is a front view of the embodiment of FIG. 2 with a nose fairing removed to show details.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S) In FIG. 1, the letter A generally indicates a duct wherein the present improved spray generator is mounted. A rotatable shaft is positioned concentrically within the duct A and is driven directly or indirectly by suitable motor means (not shown) preferably an electric motor. A rotatable sub-assembly 11 includes a hub 12; fan blades 14 secured at the hub 12 by bolts 14a; and a boss 15 mounted on the shaft 10.

A hollow coniform member 17 (central fluid distributing member) includes a central core portion 35, a rim 36 and a rounded annular forwardly projecting surface 37. The central core portion 35 is secured to the boss 15 by means of a clamp screw 16 and washer 16a. The rim 36 is connected to the forward portion of the hub 12. The hollow coniform member 17 may be formed from stainless steel, spun aluminum sheeting, corrosion resistant plastics and the like. I

A liquid supply pipe 20 has a metering valve 21 and is connected with a tubular stay 22 which, in conjunction with one or more additional stays 23, locates a liquid discharge pipe 24 in an operative position relative to the coniform member 17. The liquid discharge pipe 24 communicates with the tubular stay 22 and the supply pipe 20.

Mounted on the discharge pipe 24 is a dished fairing piece 27 having a rim 28 which is arranged so as to provide a narrow annular slit 30 between the rim l8 and the rounded annular forwardly projecting surface 37. By means of nuts 25, 26, the fairing piece 27 is positioned on the discharge pipe 24 and thereby the width of the annular slit 30 is controlled. Experimental practice shows that a normal setting-for the slit 30 is about 0.005 inch.

An alternative embodiment of the present spray generator is illustrated in FIGS. 2 and 3. Corresponding numerals will be employed to identify corresponding parts heretofore described.

In this embodiment, the stays 22, 23 support a block 32 in a fixed position relative to the rotatable shaft 10. The liquid discharge pipe 24 extends from the block 32 and communicates with the tubular stay 22 by way of a bore 31 provided in the block 32. A fixed mounting plate 33 is secured to the block 32 and extends transversely of the central axis 34 of the rotatable shaft 10.

Spacing members, such as grub screws 42, are threadedly engaged with and extend from the fixed plate 33 toward the fairing piece 27. The grub screws 42 present corresponding ends 43 engaged with a central recess portion 38 of the fairing piece 27. The central recess portion 38 has a central opening 39 which receives the liquid discharge pipe 24.

It will be observed in FIG. 3 that three of the grub screws 42 are employed the grub screws 42 being angularly spaced-apart about the central axis 34. Each of the screws 42 is supported (threaded engagement) by the fixed plate 33 for movement parallel with the central axis 34. Consequently, by proper adjustment of the individual screws 42, the rim 28 of the fairing piece 27 may be positioned (l) essentially parallel with the forwardly projecting surface 37 of the liquid distributing member 17, and (2) at a preselected distance therefrom that distance corresponding to the width of the circular slot 30.

Fastening means, such as bolts 40 and nuts 41 are provided for securing the fairing piece 27 in its adjusted position, to the mounting plate 33. Note that the bolts 40 and nuts 41 maintain the central portion 38 of the fairing piece 27 engaged with the corresponding ends 43 of the grub screws 42.

The block 32 and plate 33 may be protected from direct impingement by the liquid spray or mist, by a nose fairing 44 (FIG. 2) which is secured to the block 32 by a fastener 45.

Water or other liquid is supplied through the pipe 20, valve 21 and tubular stay 22 for discharge through the discharge pipe 24 on to the central core 35 of the coniform member 17. The liquid forms a film over the coniform member 17 as a result of centrifugal forces and the film is discharged as a fine spray through the annular slit 30 into the airstream created by the fan blades 14.

It will be seen that any foreign matter entering the space between the coniform member 17 and the dishlike fairing piece 27 will be washed out through the slit 30 along with the liquid film. Thus the present device is self-cleaning.

The amount of liquid discharged through the annular slit may be regulated by adjusting the rate of feed through the valve 21, by altering the rotational velocity of the shaft and by altering the width of the annular slit 30.

In summary, the present spray generator has a simplified construction and a reduced weight when compared with previous similar devices which establishes economies in manufacturing and transportation costs.

I claim:

1. A spray generator mounted within a duct and comprising a rotatable sub-assembly including;

central fluid distributing member having a central core portion, a rim and, therebetween, a rounded annular forwardly projecting surface;

a bladed fan disposed annularly and rearwardly of circular slit from the said annular forwardly projecting surface of the said central fluid distributing member;

pipe means disposed forwardly of the said fairing piece and extending through the said fairing piece for delivering fluid into the said central core portion of the said central fluid distributing member;

and means for rotating the said sub-assembly whereby fluid is delivered from the said pipe through the said fairing piece into the said central core portion and thence centrifugally outwardly through the said circular slit and into a stream of forwardly moving gas powered by the said fan.

2. The spray generator of claim 1 including adjustment means for setting the width of the said circular slit.

3. The spray generator of claim 2 wherein said adjustment means are operable to establish the location of the said fairing piece.

4. The spray generator of claim 2 wherein said adjustment means comprises:

said fairing piece having a central portion disposed concentrically about said central axis;

a fixed mounting plate disposed forwardly of said fairing piece, confronting said central portion, and extending transversely of said central axis;

spacing members extending from said mounting plate, disposed in angularly spaced-apart relation about sat central axis, an having corresponding ends engaged with said central portion, each of said spacing members being supported by said mounting plate for movement toward and away from said central fluid distributing member; and fastening means for securing said fairing piece to said fixed mounting plate with said central portion engaged with the corresponding ends of said spacing members. 

1. A spray generator mounted within a duct and comprising a rotatable sub-assembly including: central fluid distributing member having a central core portion, a rim and, therebetween, a rounded annular forwardly projecting surface; a bladed fan disposed annularly and rearwardly of the said rim; both said fan and said central fluid distributing member being adapted to rotate as a sub-assembly about a common central axis which is substantially parallel to the longitudinal axis of the said duct; a fixed, dished fairing piece having a perimeter which is disposed concentrically about the said central axis and having a rim which is spaced-apart by a circular slit from the said annular forwardly projecting surface of the said central fluid distributing member; pipe means disposed forwardly of the said fairing piece and extending through the said fairing piece for delivering fluid into the said central core portion of the said central fluid distributing member; and means for rotating the said sub-assembly whereby fluid is delivered from the said pipe through the said fairing piece into the said central core portion and thence centrifugally outwardly through the said circular slit and into a stream of forwardly moving gas powered by the said fan.
 2. The spray generator of claim 1 including adjustment means for setting the width of the said circular slit.
 3. The spray generator of claim 2 wherein said adjustment means are operable to establish the location of the said fairing piece.
 4. The spray generator of claim 2 wherein said adjustment means comprises: said fairing piece having a central portion disposed concentrically about said central axis; a fixed mounting plate disposed forwardly of said fairing piece, confronting said central portion, and extending transversely of said central axis; spacing members extending from said mounting plate, disposed in angularly spaced-apart relation about said central axis, and having corresponding ends engaged with said central portion, each of said spacing members being supported by said mounting plate for movement toward and away from said central fluid distributing member; and fastening means for securing said fairing piece to said fixed mounting plate with said central portion engaged with the corresponding ends of said spacing members. 